Frequency-responsive relay and indicator



Sept. 23, 195

Filed June 29, 1956 A. w. DASCHKE ET AL 2,853,677

FREQUENCY-RESPONSIVE RELAY AND INDICATOR 2 Sheets-Sheet l 1 I I Il/W/lK/I 1 7 1 I l by INVENTORS Arthur: W Dasfcfike BY WL ZZLQHZ 6 s ezzWQM AGE/VT I Sept. 23, 1958 A.4W. DASCHKE ET AL FREQUENCY-RESPONSIVERELAY AND INDICATOR Filed June 29, 1956 2 Sheets-Sheet 2 HIM/44 UnitedStates Patent FREQUENCY-RESPONSIV E RELAY AND INDICATOR Arthur W.Daschke, Morristown, and William G. Snell,

Rockaway, N. J., assignors to J-B-T Instruments, Inc.,

This invention relates to frequency-responsive devices, and moreparticularly to frequency-responsive electrical relay mechanisms.

In the past there have been provided a number of electro-responsivedevices intended to effect a control when the frequency of impressedenergy attained a certain value. Some devices intended for this purposehave been in the nature of frequency meters having vibratile reeds, andhaving incorporated therein electrical contacts adapted to be actuatedwhenever the impressed energy has a given frequency. Such devices aresubject to a number of drawbacks. For one thing, the action of thecontacts is of necessity characterized by extremely light pressure, andaccordingly may at times be unreliable. For another thing, all contactsof necessity have a certain weight and mass, and this must be accuratelydetermined and accounted for in the vibratile system, in order that theaccuracy in the indication and reliability of the control be maintained.

A still further drawback of these prior devices resided in the fact thatthe contact was of an intermittent nature and not steady, andaccordingly allowance had to be made or further equipment had to beprovided, if such operating characteristic were not suitable for thedesired end result.

The above drawbacks and disadvantages of these priorfrequency-responsive devices or relays are obviated by the presentinvention, and one object of the invention is to provide a novel andimproved frequency-responsive relay which provides a positive, firm andsteady electrical contact, to effect the desired condition or control.

Another object of the invention is to provide an improved relay deviceas above set forth, wherein dependence is not had on lightly-touching orintermittentlytouching contacts.

A further object of the invention is to provide an improved frequencyrelay as above set forth, which is characterized by constantly closed orconstantly open electrical contacts associated with but not carried bythe vibratile elements, the organization being such that no permanentmechanical connections to said elements is necessary nor permanentengagement therewith by any movably mounted parts or components.

Still another object of the invention is to provide an improved relaydevice of the type having vibratile elements, wherein there are noadverse effects on the resonant period of said elements by such factorsas impact forces or sticking between engaging contacts.

Yet another object of the invention is to provide a novel and improvedvibratile-element type of frequencyresponsive relay which is devoid ofall contacts on the said elements.

A further object of the invention is to provide an improvedfrequency-responsive relay wherein an indication or control is effectedby contacts which are separate from the vibratile elements and are underthe influence of magnetic flux.

A still further object of the invention is to provide an improvedfrequency-responsive relay'as above set forth, which incorporates afrequency meter movement by which both an indication and control is had,in response to frequency changes in a source of electrical energy.

An important feature of the invention resides in the provision of afrequency-responsive relay having magnetically influenced contacts asabove set forth, wherein there is minimized the effects on the contactsof stray flux from the driving coil for the vibratile elements.

Another feature of the invention resides in the provision of an improvedfrequency-responsive device of the above type, which is relatively smalland compact, requiring but little space.

Other features of the invention reside in the provision of an improvedfrequency-responsive meter and relay device as above characterized,which hashigh sensitivity, is extremely simple in its construction,economical to fabricate, and reliable in operation.

Still other features and advantages will hereinafter appear.

In the drawings accompanying this specification, similar characters ofreference indicate corresponding parts wherever possible in the severalviews, in which:

Figure 1 is an axial sectional view of a frequencyresponsive relay andmeter made in accordance with the invention.

Fig. 2 is a front elevational view of the device shown in Fig. 1.

Fig. 3 is a schematic circuit diagram of a signal system embodying theimproved frequency relay and meter.

Fig. 4 is a fragmentary front elevational view on the order of Fig. 2,but illustrating another embodiment of the invention, wherein a singlereset solenoid is employed.

Fig. 5 is a fragmentary axial sectional view somewhat like Fig. l, butillustrating a wholly mechanical or manual type of reset device.

Fig. 6 is a fragmentary elevational view taken on line 6-6 of Fig. 5.

As shown, the improved frequency meter and fre-' quency-responsive relayof the present invention comprises a casing 10 having a transverse rearor back wall 11 and a transparent front window 12, the latter beingdisposed within a peripheral mounting flange 13.

Within the casing 10 and behind the window 12 there is provided a scale14 having indicia 15 indicating frequency values or other desired data.

The scale 14 is carried by U-shaped brackets 16 mounted as shown on therear transverse wall 11 of the casing 10. Also carried by the brackets16 is a permanent magnet 17 adapted to provide a magnetic field or fluxpattern for a plurality of vibratile reeds 18 carried by mounts 19secured by means of a block 20 to the brackets 16. The reeds 18 may beof any usual number, nine being shown in Fig. 2, correspondingrespectively to five cycle intervals in a frequency band of from 380 to420 C. P. S.

The reeds 18 thus constitute a set, having respective resonant periodsfive cycles apart. To actuate the reeds 18 there is provided a drivingcoil 22 encircling the same and carried by a coil bracket 23 secured tothe U-shaped brackets 16.

In accordance with this invention there is provided a novel andimproved, greatly simplified and yet extremely effective relay orcircuit-controlling means adapted to be actuated when either of theextreme end reeds 18 of the set is caused to oscillate by virtue of thefrequency of such reed occurring in the coil 22. Thus, an indication ora control may be had at a remote point, whenever the frequency impressedon the coil 22 drops to 380 C. P. S. or rises to 420 C. P. S. Thisimproved circuitcontrolling or relay means is independent of allpermanent connections to the reed 18 yet is adapted to have certainforces or impulses transmitted to it momentarily a by such reeds duringsubstantial oscillations of the latter. The circuit controlling means ischaracterized by contacts which are magnetically influenced or operated,both for closing the circuit and also thereafter for opening thecircuit.

As shown, we provide a pair of movable contact members and 26 which arepreferably also vibratile and are carried by means of mounting blocks 28and 29 on the rear transverse wall 11 of the casing 10. The vibratilecontacts 25 and 26 are in the nature of reeds extending forwardly fromthe transverse wall 11 substantially parallel to the reeds 18 and attheir front extremities having angularly bent end portions 25a and 26aextended toward the end reeds 18 and adapted to be struck by the latterwhen either of said reeds is oscillating in synchronism with a frequencyapplied to the driving coil 22. Normally, as shown in Fig. l, the meterreeds 18 and the bent extremities 25a and 26a of the members 25 and 26are spaced apart a certain distance. However, should either of the twoend reeds 18 oscillate appreciably, it will strike the associated one ofthe members 25, 26 and cause the latter to be deflected.

By the present invention, such deflection is utilized to effect acontinuous closing of an electrical circuit, and in accomplishing thiswe provide a pair of electrical contact members 30 and 31 carryingpermanent bar magnets 32 and 33 respectively, said magnets being inclose proximity to the members 25 and 26. Also, the said members 25 and26 are made magnetic, so as to be attracted by the magnets 32 and 33.Normally, when there is no activity of the end reeds 18 of the meter,the contact members 25 and 26 will remain spaced from the contacts 30and 31. However, upon either of the end reeds 18 vibrating and strikingthe associated member 25, 26, the deflection imparted to said memberwill be sufficient to enable the magnetism from the magnets 32 or 33 toattract and shift the member, causing engagement of the latter with themagnet and therefore with the contact member 30 or 31 carrying themagnet. Thus a circuit will be closed between either of the members 25,26 and the associated contact member 30, 31 as a consequence of one ofthe end reeds 18 being set into synchronous vibration. The attractiveforce of the magnets 32, 33 will retain the contacts thus established,maintaining the circuit closed even though the end reed 18 which hascaused said closure should stop vibrating. Thus a latching effect ishad, and the present frequency-responsive relay may thus be consideredas a latching relay.

For the purpose of separating the members 25, 26 from their associatedmagnetic contacts 32, 33 there are provided solenoids 34 and 35, havingplungers 36 adapted to engage and drive the members 25, 26 from right toleft, as viewed in Fig. 1. Thus energization of either of the solenoids34 or will be effective to open the circuits controlled by the members25, 26, at the will of the operator.

We have found that, by the above organization, there is provided anextremely simple, effective and reliable latching-type relay which ishighly sensitive and responsive to certain predetermined frequencies.With the instrument as shown, frequencies of either 380 or 420 C. P. S.impressed on the driving coil 22 will cause closure of one or the otherof the controlling circuits associated with the members 25, 26. Thus aremote indication may be had of the shift of frequency, or a control toreverse the frequency shift, in accordance with Well-known procedures.The control for reversing the frequency shift may also be utilized toenergize momentarily the proper one of the solenoids 34, 35, thereby toagain interrupt and open the controlling circuit.

It is preferred that the members 25 and 26 have a frequencysubstantially different from that of the end reeds 18 which impartforces to said members, the frequencies of said members being preferablyof a lower order of magnitude so as to prevent undue influence on themembers of stray flux from the driving coil 22.

A circuit illustrating the use of the frequency relay of the inventionis shown in Fig. 3, wherein the contact reeds 25 and 26 are connectedwith leads 39 and 40 respectively leading to high and low electricalsignals 41, 42, said signals being connected to a supply wire 43energized by a battery 44. A common lead joins the contacts 32 and 33 tothe batery 44. It will be understood that the signals 41, 42 may beelectric bulbs, buzzers or any other desired type of signal means.

' Another embodiment of the invention is shown in Fig. 4, wherein thereset comprises a single solenoid 46 having a plunger 47 to which thereis attached a reset bar 48 adapted to engage the contact reeds 26 and25. Energization of the solenoid 46 will cause movement of the reset bar38 from right to left, as viewed in Fig. 4, thereby to disengagewhichever one of the contact reeds 25 or 26 is being held by theassociated magnet contact.

A still further embodiment of the invention is illustrated in Figs. 5and 6, wherein a wholly mechanical or manual reset device is providedinstead of the solenoid actuated reset devices shown in the precedingfigures.

Referring to Fig. 5, the window 12 has secured to it a bearing bushingBil in which there is turnably carried a spindle 51 having amanually-engageable knob 52 which is normally held in a predeterminedrotative position by a torsion spring 53. The spindle 51 carries a resetbar 54 arranged to engage either one or the other of the contact reeds25, 26, to disengage the same from its associated contact upon a properturning movement being imparted to the knob 52. Upon release of the knob52, the spring 53 will, of course, return the reset bar 54 to a neutralposition wherein either of the reeds 25, 26 may engage its associatedcontact.

It will be understood that with the improved contact organization asprovided by this invention, an appreciable current capacity is availableto handle the signals 41 and 42 without requiring further relays oramplification. This is because the inertia of the contact reeds 25, 26does not enter into the vibration characteristics of the indicatingreeds 18, and therefore the contact reeds may be designed to obtain thefull benefit of a relatively large current carrying capacity.

Variations and modifications may be made within the scope of the claimsand portions of the improvements may be used without others.

We claim:

1. A frequency-responsive relay comprising a vibratile member adapted tovibrate at a given frequency, said member having portions of low andhigh amplitude of vibration; means for causing vibration of saidvibratile member; a movable member normally held in a given positionspaced from the vibratile member when the latter is at rest, saidmovable member having portions of low and high amplitude of vibration;means for moving said movable member in a direction away from said givenposition and holding said member in a second position in response toinitiation of movement of said member toward said second position saidmeans including a third member at all times at least closely spaced fromsaid movable member; circuit controlling means actuated in response tomovement of said movable member between said positions; and means forimparting force to said movable member in response to vibration of thevibratile member at its given frequency whereby the movable member iscontinuously held in said second position, said force-imparting meansincluding a driving connection between the high-amplitude portions ofsaid members, said connection being substantially inoperative to impartforce when the movable member is in its said second position, thevibratile member being thereby substantially wholly free forsubstantially unhampered high-amplitude vibration as a consequence ofits initial vibration at its said given frequency.

2. The invention as defined in claim 1 in whichthere is anoptionally-operable means for returning the said movable member from thesaid second-mentioned positionto the said given position.

3. The invention as defined in claim 2 in which the optionally-operablemeans comprises a solenoid having a plunger adapted to actuate the saidmovable member.

4. The invention as defined in claim 1 in which the movable member isvibratile and adapted to vibrate in response to impulses applied to it.

5. The invention as defined in claim 4 in which the movable member has aresonant frequency substantially removed from the frequency of thevibratile member.

6. The invention as defined in claim 5 in which there is a driving coilfor causing vibration of the vibratile member, and in which the saidmovable member is magnetic and disposed in the field of influence of thesaid driving coil.

7. The invention as defined in claim 5 in which the vibratile member andthe movable member comprise reeds disposed in spaced, parallel relationto each other, and in which there is a driving coil disposed at one sideof the movable member and surrounding the vibratile member to impartoscillations to the latter.

8. The invention as defined in claim 7 in which the means for moving andholding the movable member comprises a permanent magnet disposedadjacent the side of said member which is away from the driving coil,and in which there is a second permanent magnet disposed adjacent thedriving coil and located remote from said firstmentioned magnet, saidsecond permanent magnet providing a field for the said vibratile member.

9. The invention as defined in claim 4 in which the means for moving andholding the movable member comprises magnetic material thereon and apermanent magnet adapted to attract said magnetic material.

10. The invention as defined in claim 9 in which the circuit controllingmeans comprises contacts respectively on the movable member andpermanent magnet.

11. The invention as defined in claim 1 in which the means for movingand holding the movable member comprises a permanent magnet and amagnetic armature therefor.

12. The invention as defined in claim 2 in which the movable membercomprises a reed anchored at one end, in which the means for moving andholding the movable member comprises a permanent magnet disposedadjacent the free end of the member, and in which the optionallyoperablemeans comprises a solenoid disposed adjacent the anchored end of themember.

13. A frequency-responsive relay device comprising a set of juxtaposedvibratile members having different resonant frequencies, each of saidmembers having different portions of low and high amplitude ofvibration; a scale having indicia to which said members may be referred;means for causing vibration of said vibratile members; a pair of movablemembers associated respectively with two vibratile members of said set,each of said movable members having different portions of low and highamplitude of vibration, said members being normally held in givenpositions spaced from the respective vibratile members when the latterare at rest, the high-amplitude portions of said vibratile and movablemembers being juxtaposed; means for moving said high-amplitude portionsof said movable members in directions away from said given positionsandholding said portions in second positions in response to initiation ofmovements of said members toward said second positions, said movingmeans including a pair of third members respectively as sociated withsaid movable members and at all times at least closely spaced therefrom;circuit controlling means actuated in response to movements of saidhigh-amplitude portions of the movable members between said positions;and a pair of means for imparting forces respectively to said movablemembers in response to vibration of the vibratile members at their givenfrequencies, a

to cause the said initial movements of the movable members whereby thesame are in consequence continuously held in their said secondpositions, said force-imparting means including driving connectionsbetween the highamplitude portions of said vibratile and movablemembers, said connections being substantially inoperative to impartforce when the movable members are in their said second positions, thevibratile members being thereby substantially wholly free forsubstantially unhampered high-amplitude vibration as a consequence oftheir initial vibration at their said given frequencies.

14. A combined frequency meter and frequency-responsive relay devicecomprising a set of juxtaposed vibratile reeds having free ends andhaving diiferent resonant frequencies; a driving coil surrounding saidreeds; a scale having indicia, to which said reeds may be referred; apair of flexible strips disposed outside of the driving coil andassociated "respectively with two vibratile reeds of said set, saidflexible strips being spaced from the vibratile members when the latterare at rest and being normally held in given positions; means for movingsaid strips in directions away from said given positions and holdingsaid strips in second positions in response to initiation of movementsof said strips toward said second positions, said means includingmagnets at all times at least closely spaced from said stripsrespectively; circuit controlling means actuated in response tomovements of said strips between said positions; and means for impartingforces to one or the other of said strips to cause the said initialmovement thereof in response to vibration of one or the other of thesaid two vibratile reeds at its given frequency, the high-amplitudeportions of said reeds and strips being juxtaposed and engageable witheach other when the strips are in the said given positions, said reedsvibrating freely at high-amplitude and being out of contact with saidstrips when the latter are in their second positions.

15. The invention as defined in claim 2 in which the optionally operablemeans for returning the movable member comprises a movably-mountedoperable part having an extension adapted to actuate the said movablemember.

16. The invention as defined in claim 13 in which there is anoptionally-operable means for returning said strips from thesecond-mentioned positions to the said given positions, said optionallyoperable means comprising a movably-mounted, manually-operable memberhaving a pair of extensions adapted to respectively engage said strips.

17. A combined frequency meter and frequency-responsive relay devicecomprising a vibratile member adapted to vibrate at a given frequency,said member having diflerent portions of low and high amplitude ofvibration; a driving coil surrounding said vibratile member; a scalehaving indicia, to which said vibratile member may be referred; amovable member disposed outside of the driving coil and associated withsaid vibratile member, said movable member having different portions oflow and high amplitude of vibration and being normally held in a givenposition wherein the high-amplitude portion thereof is spaced from thevibratile member when the latter is at rest, both high-amplitudeportions of said vibratile and movable members being juxtaposed; meansfor moving the high-amplitude portion of the movable member in adirection away from the said given position and for holding said portionin a second position in response to initiation of movement of saidhigh-amplitude portion toward said second position, said moving meansincluding a third member at all times at least closely spaced from saidmovable member; circuit-controlling means actuated in response tomovement of said high amplitude portion of the movable member betweenthe said positions; and means for imparting force to said movable memberin response to vibration of the vibratile member at its given frequency,to cause the said initial movement of the movable member whereby thesame is in consequence continuously held in said second position, saidforce-imparting means including a driving connection between thehigh-amplitude portions of said members, said connection beingsubstantially wholly free for substantially unhampered high-amplitudevibration as a consequence of its initial vibration at its said givenfrequency.

18. A combined frequency meter and frequency-responsive relay devicecomprising a set of juxtaposed vibratile members adapted to vibrate atdifferent given resonant frequencies, each of said members havingdifferent portions of low and high amplitude of vibration; a drivingcoil surrounding said members; a scale having indicia, to which saidmembers may be referred; a pair of movable members disposed outside ofthe driving coil and associated respectively with two vibratile membersof said set, each of said movable members having differentportions oflow and high amplitude of vibration and being normally held in a givenposition spaced from its associated vibratile member when the latter isat rest, the high-amplitude portions of said vibratile and movablemembers being juxtaposed; means for moving the highamplitude portions ofsaid movable members in directions away from said given positions andfor holding said portions in second positions in response to initiationof movements of said high-amplitude portions toward said secondpositions, said moving means including a pair of third membersrespectively associated with said movable members and at all times atleast closely spaced therefrom; a circuit-controlling means actuated inresponse to movements of said high-amplitude portions of the movablemembers between the said positions thereof; and a pair of means forimparting forces respectively to said movable members in response tovibration of the vibratile members at their given frequencies, to causethe said initial movements of the movable members whereby the same arein consequence continuouslyheld in their second positions, saidforce-imparting means including driving connections between thehigh-amplitude portions of said vibratile and movable members, saidconnections being substantially inoperative to impart force when themovable members are in their said second positions, the vibratilemembers being thereby substantially wholly free for substantiallyunhampered high-amplitude vibration as a consequence of their initialvibration 'at their said given frequencies.

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